Sequence Stratigraphic Setting of the Neogene Sediments, Mississippi Canyon and Northern Atwater Valley, Northeastern Deep Gulf of Mexico
Paul Weimer, Renaud Bouroullec, Jay Austin, John Roesink, Hector Gonzalez, John Martin, Ryan Sincavage, David Pyles, Veit Matt, and Sarah Melton
Department of Geological Sciences, University of Colorado, Boulder, Colorado
The sequence stratigraphic setting of the central and southern Mississippi Canyon, Atwater Valley, and Lloyd Ridge protraction areas are described using 19,557 miles of 2-D seismic, 387 square miles of 3-dimensional seismic, 160 wireline logs and biostratigraphic data. Twelve depositional time intervals are interpreted: 24, 15.3, 13.0, 10.75, 9.0, 7.45, 6.2, 5.5, 4.1, 3.6, and 1.3 Ma.
The area consists of a multi-level allochthonous salt system that developed throughout the Mesozoic-Cenozoic. To the east, the area consists of a largely unstructured slope with unconfined turbidite systems extending from shelf to the base-of-slope. Oil and gas fields in this area consist primarily of channel-fill reservoirs lapping out against salt structures.
Towards the west, the area changes to a series of complex intraslope minibasins created from salt, basement, and strike slip deformation. Turbidite systems began to pond against the growing salt structures at about 15 Ma. Turbidite elements include the stacking of sheets, channels, overbank, and slides in predictable patterns. The intervals with the largest net sand content are deposited in (1) early stages of allochthonous salt withdrawal where accommodation is actively created, (2) between salt bodies, and (3) in the unconfined abyssal plain where they are deformed to structures, e. g. turtles, foldbelt.
AAPG Search and Discovery Article #90032©2004 GCAGS 54th Annual Convention, San Antonio, Texas, October 10-12, 2004